MAE SARIANG, Thailand—Thai authorities on Monday denied forcing back more than 2,000 refugees who had fled air strikes in Burma, but a local official said it was government policy for the army to block them at the border and deny access to outside aid groups. Thousands of people fled Burmar (also known as Myanmar) over the weekend after fighter jets attacked villages near the border held by a force from the Karen ethnic group that had attacked a military post in the wake of a Feb. 1 coup by Burma’s army. Mark Farmaner, head of Burma Campaign UK, told Reuters that thousands of people had been forced to return to the Ee Thu Hta displacement camp on the Burma side of the border. Another activist group gave the number as 2,009. Video shot by a Karen villager and published by Reuters showed refugees boarding boats under the watch of Thai …